BEIRUT, LEBANON - Israeli soldiers clashed with Lebanese Hezbollah guerrillas along the border Tuesday, leaving two soldiers and one guerrilla dead and prompting an Israeli general to threaten Hezbollah and its sponsors — Syria and Iran.

The renewed fighting, the most serious in months, followed a bombing Monday in Beirut that killed a veteran Hezbollah commander.

Hezbollah blamed Israel for the assassination, but the Israeli army denied involvement.

Israel and Hezbollah traded blame Tuesday over who started the fighting. Lebanon's government complained to the U.N. Security Council about the attacks, saying Israel violated Lebanese airspace, killed a Lebanese guerrilla fighter and caused material damage, a Foreign Ministry official said on condition of anonymity.

Unlike most of the previous clashes, Tuesday's incidents were far from the disputed Chebaa Farms, where Israel and Hezbollah frequently exchange gunfire.

The Israeli army said two soldiers died Tuesday and helicopter gunships attacked Hezbollah positions.

Witnesses in southern Lebanon said two Israeli helicopters fired rockets at guerrillas near the border village of Aita Shaab, about nine miles southeast of coastal Tyre. Later, an Israeli helicopter targeted the same area, security officials said.

The Lebanese security officials, speaking on condition of anonymity, said an Israeli tank fired on a Hezbollah position near Aita Shaab, killing one guerrilla. Hezbollah returned fire across the border. Israeli helicopter gunships later fired back, the officials said.

A Hezbollah statement said the guerrilla was killed by an Israeli tank shell targeting a Hezbollah observation post near Aita Shaab late Tuesday morning.

Israeli helicopters then attacked another observation post at nearby Ramia, but there were no casualties or damage, Hezbollah said.

The militant Shiite Muslim group vowed it would "choose the time and place for a deterrent response to make the enemy understand that aggression against the security and blood of our people would be very costly."

In Israel, Maj. Jacob Dallal of the military spokesman's office said Hezbollah fired first at an Israeli border post and Israeli military action responded to the "provocation."

Later, Maj. Gen. Benny Gantz, the Israeli area commander, said the day was not "far away" when Israel would "act widely, severely."

"I don't believe Hezbollah will be the only address at that time. I think this is a matter of state responsibility, and these two countries (Syria and Iran) that host and direct financing and training Hezbollah organization will end up paying its price," he said.